Sheet handling devices



United States Patent [22] Filed June 17, 1968 [4S] Patented Dec. 15,1970 [73] Assignee USM Corporation Flemington, NJ.

a corporation of New Jersey [54] SHEET HANDLlNG DEVICES 4 Claims, 5Drawing Figs.

[52] U.S. Cl 271/20, 271/19, 271/25 [51] Int. Cl B65h 3/08, B65h 3/22,B65h 3/30 [50] Field ofSearch 271/1l,5, 19, 20, 24, 25, 26, 30, 31

[56] References Cited UNlTED STATES PATENTS 326,124 9/1885 Kneeland27l/20 2,003,698 6/1935 Remington 271/25 871,498 11/1907 Graham 271/20754,204 3/1904 Dexter 271/20 1,110,704 9/1914 Minnick. 271/20 2,554,3205/1951 Battey 271/20 Primary Examiner-Richard E. Aegerter AssistantExaminer- Roger S. Gaither Attorneys-W. Bigelow Hall, Richard A. Wiseand Aubrey C.

Brine ABSTRACT: A machine for feeding a preselected number of flexiblesheets of material from a stack of sheets which includes a device foreffecting release from the stack of only the selected number of sheetsto be fed. The device has an element which engages the face sheet of thestack and moves it in a direction toward a point on the stack wherepressure is applied by another element of the device. The operation isperformed on each successive underlying sheet that is desired to be fed,forming a buckle in each of the sheets and thereby separating it fromits underlying sheets, after which the remainder of the stack is clampedand the preselected number of sheets are fed from the stack.

PATENTED DEC] 5 i976 SHEET 2 OF 3 SHEET HANDUNG DEVICES BACKGROUND OFTHE INVENTION The present invention relates to a machine for feedingflexible sheets from a stack and in particular to a device for effectingrelease of a preselected number of sheets to be fed from the stack.

One of the problems which has existed in the past in the sheet-feedingart has been that of reliably feeding only a Single sheet of materialfrom a cut stack of sheets, The problem has prevailed for many years,particularly in the garment industry, where much of the fabric feedingfrom a stack has heretofore been done by hand labor.

Various devices have been developed to accomplish this task, for examplethose described in US. Pat. Ser. No. 647, 784, filed June 21, 1967 inthe name of Richard R. Walton, and U.S. application Ser. No. 668,574,now U.S. Pat. No. 3,430,949 filed Sept. l8, 1967 in the names ofDonaldF. Herdeg and Paul E. Morgan, now U.S. Pat, No. 3,430,949 both as signedto the assignee of the present invention. These devices have provedsuccessful in the handling of a great variety of materials by providingautomatic machinery which is both efficient and reliable in feeding asingle sheet from a stack and stacking it at a selected location.

However, a second and perhaps moredifficult problem exists when itbecomes desirable to feed a preselected number of sheets in registryfrom a stack. Such a situation quite often exists in the field ofapparel manufacturewhere the next operation after unstacking the sheetsis that of seaming, bonding, stitching or otherwise operating on thesheets while in the mated condition. Here, as in the operation where asingle sheet is to be fed from the stack, it is of the utmost importancethat only the preselected number of sheets be presented to the workstation such that unnecessary cost of rejecting the finished product beeliminated. A machine constructed for the aforementioned purpose,therefore, must be simple and reliaole in operation such that only thepreselected number of sheets of material are fed from the stack to thesubsequent work station. The machine must further be capable ofoperating on a great many different kinds of materials wherein thesingle sheets themselves may vary over a wide range of thickness, degreeof porosity and flexibility, or where there is a frictional variationamong the sheets of the stack.

ln presently existing machines, one of the basic problems is that ofseparating the preselected number of sheets from the stack, so that theymay be cleanly removed from the underlying sheets. Thus, when it isdesired to remove one, two, three, etc. sheets fromthe face of the stackin registry by a single pickoff operation, the operator should have theability by simple adjustment to separate the preselected number ofsheets such that they may be removed cleanly from the stack of material.

The present invention therefore has as an object to provide a machinefor feeding a preselected number of sheets of material from a stack, themachine being both effective and reliable to feed single or multiplesheets having a wide range of material characteristics and thickness;

Another object of the invention is to provide a machine for feedingsheets of material from a stack, the machine having a device which iscapable of separating only the selected number of sheets to be fed fromthe stack.

A further object of the invention is to provide a sheetseparating deviceto be employed in a sheet feeder which device is simple in constructionand readily adjustable to separate only a preselected number of sheetsfrom a stack thereof.

SUMMARY OF THE INVENTION These objects of the invention, and otherobjects which will become apparent as the description proceeds, areachieved by providing a machine for feeding flexible sheets of material,such as fabric, from a stack wherein a pickoff means is employed forengaging the face of the stack and removing a plurality of sheets, or asingle sheet, as is desired to be fed from the stack.

A device for separating the sheets is provided in the machine whichcomprises a means for engaging the surface of the face sheet of thestack and means for moving the surfaceengaging means in a directionhaving a component substan tially parallel to the face of the stack toslide the engaged sheet over the underlying sheets in the stack. Aplurality of the sur face-engaging means are employed, and operated insequence, when it is desired to feed more than one sheet from the stack.When the selected number of sheets have been separated by thesurface-engaging means, means for applying a clamping pressure to theunderlying sheets of the stack is applied in the area where the sheet orsheets have been removed from the underlying sheets, to thus retain thestack while the pickoff means is operated to remove the sheet, orsheets, from the stack.

Generally a pressure-applying means is disposed in the direction ofmovement of the surfacc-engaging means, and is effective when applied tothe face of the stack to produce a buckle in the sheet of material beingmoved by the surface-engaging means. The forming of the buckle thusreleases the sheet being operated on from the underlying sheet byproviding a lack of frictional engagement with the undcrlyingshcet, overthe buckled area. Those sheets having such lack of drug are then cleanlyremoved by the sheet p'ckoff means without disturbing the underlyingsheets which are held together by a clamping means applied to theunderlying sheets of the stack and by frictional engagement.

The sheet or sheets so separated from the stock remain in alignmentduring separation, but for the separator locations, and it is thereforepossible to retain alignment of the sheets during the separation andpickoff process, if desired.

The pressure-applying means of the device is considered to establish ashort length of column in a sheet from its point of application to theplace where the surface-engaging means contacts the sheet. The area ofcontact between the face sheet and the underlying sheet is generallysmall relative to. the total area of the sheet, thus, very littlepressure need be applied to the surface-engaging means to break thefrictional lock over this area. As the engaging means scuffs the sheetportion towards the pressure-applying means, the column thus formed inthe face sheet experiences a buckling, forming an S-curve of bending, orbuckle, in the sheet. Theunderlying ply, if still being carried byfrictional attachment (fiber entanglement or surface roughness) to theface sheet, resists such buckling, as only a negligible force is beingapplied to this sheet in the direction of the pressure-applying means.The resistance to buckling of the underlying sheet causedby the columneffect together with the buckling of the face sheet thus overcomes anyfrictional lock between the two sheets and the underlying sheet fallsback to its flat condition, where it is clamped with the remainder ofthe stack.

In general, the separating devices are employed in pairs, each beingprovided at a corner of the stack of sheets rearwardly of the pickoffmeans. The devices are generally so ar ranged that the surface-engagingmeans in their operation to release a sheet from the stack are movedwith a component toward one another, or diagonally from the cornerstoward the center of the stack face.

BRIEF DESCRIPTION OF THE DRAWlNGS FIG. I is an elevational view showingan illustrative machine embodying the invention for feeding sheets ofmaterial such as fabric or the like, in which the present invention isembodied;

H6. 2 is atop plan view taken along the line ll-ll of H6. 1, and showingdetails of the invention taken on an enlarged scale for clarity;

FIG. 3 is a side elevational view, partly in section, taken along thelines Ill-Iii of FIG. 2 and showing details of the separating device asdepicted in FIG. 2;

- FIG. 4 is a side elevational view similar to that of FIG. 3 butshowing the various elements of the device at another point in timeduring its operation; and

FIG. 5 is a side elevational view similar to FIGS. 3 and 4 but showingthe various elements of the device taken at yet another point in timeduring machine operation.

DESCRIPTION OF THE PREFERRED EMBODIMENT While it is considered that theprinciples of the invention are broadly applicable to machines forfeeding flexible sheet vlr'naterial from a stack, the invention has beenherein illustrated in a machine for feeding sheets of fabric material,and will be so described.

f Referring to the drawings, and in particular FIG. 1, there is shown amachine for feeding flexible sheet material such as -"fabric, which hasbeen constructed in accordance with the teachings of the presentinvention and which includes a frame I0 having an elevator 12 mountedthereon for movement in the vertical direction. Adjacent the upperportion of the frame while the lower sprocket 30 is driven in'bo th theclockwise and counterclockwise direction by suitable motor means (notshown).

The elevator 12 further comprises a substantially horizontal surface 32on which a pallet -34 bearing a stack S of flexible pieces of materialsuch as fabric may be located.

7 With the structure thus far described it will be observed thatmovement of the sprocket 30 in counterclockwise direction as viewed inFIG. 1 is effective to cause the elevator 12 to move upwardly along thetrack 22, while clockwise directional movement of the sprocket 30 iseffective to cause the elevator 12 to move downwardly.

= The carrier arm 14 comprises housing'38 having a lug 40 provided atone end thereof. The lug 40'has a cylinder 42 pivotally connected to itwhich cylinder extends forwardly along the length of the arm 14. Thecylinder 42 is of the double action-type which may be operated by asuitable source of fluid pressure (not shown). A carriage support rod 44is affixed to the housing 38 at a point forward of the lug 40, andextends longitudinally along the greater portion ofthe arm 14. Referringstill to FIG. 1, it will be observed that the work head comprises acarrier member 46 attached to a housing 48 which is slidably mounted onthe rod 44. The sliding housing 48 and the carrier member 46 provide acarriage assembly for the various elements of the sheet pickoff deviceand movable along the rod 44 over a lengthwise portion of the carrierarm I4. The cylinder 42 is provided with a piston rod 50 pivotallyattached to the forward end of the housing 48 to connect the cylinder 42to the carriage assembly.

I The carrier member 46 is shown to be provided with a downwardlyextending portion to which a horizontally extending mounting plate 54 isattached. The plate 54 is generally provided with a plurality of slottedopenings through which threaded fasteners 57 extend to support aplurality of tubular members 58.

The carrier arm 14 is provided with a pair of limit switches LSI and LS2affixed at the extreme ends of the arm. The housing 48 is in turnprovided with an outwardly extending flange 60 having an upper surfacealigned for contact with the act'ivating rollers of the switches LS1 andLS2. These switches LS1 and LS2 are operatively connected in a controlcircuit which is effective to energize the various air valves and motorswhich operate the cylinder 42, the elevator 12 and which provides fluidfor the pickoff means employed in the machine.

Additionally, the switches LS1 and LS2 may be used in conjunction with asuitable circuitry to initiate operation of, and time delay sequences inthe novel-separating device which will be described in greater detail asthe description proceeds.

The device thus far described, is similar in detail and in operation tothat described in US. application Ser. No. 668,574, filed Sept. 18, I967in the name of Herdeg et al., which application has previously beenalluded to. As in the above-mentioned application, the present device isgenerally provided with a pickoff means for removing the face sheet, orpreselected number of sheets from the stack and delivering the sheet orsheets to the desired location. The pickoff means generally designatedby the numeral 62 may be of the type described in detail in US. allowedPat. application Ser. No. 647,784, tiled June 2l, 1967 in the name ofRichard R. Walton. However, the device may be modified in accordancewith the aforementioned I-Ierdeg application, or may be of the type morerecently described in copending US. application Ser. No. 737,580, filedJune 17, I968 in the name of Mason et al. As each of the aforementionedpickoff means is considered to be adequately described in the referencepatent application. it is herein sufficient to state that the choice ofany one of these, or other pickoff devices, may be made to meet theparticular requirements of the application with regard to material to behandled as well as the number of sheets to be removed, and the precisionrequired in stacking or mating at the location of deposit of the sheetsor sheet.

Referring now to FIGS. 2 and 3 taken in connection with FIG. 1, it willbe observed that a T-shaped support member 64 is attached to the frame10 above the elevator 12; At each end of the cross portion of theT-shaped member 64 there is provided a sheet-separating device 66comprising a mounting plate 68 which is disposed on the member 64. Apair of slotted openings 70 are provided in the plate 68, and a pair offasteners 72' are received therethrough 'to connect the device 66 to themember 64 in-a manner providing for lateral adjustment of the devicealong the cross portion of the T-shapcd member.

Each of the devices 66 are identical in structure and in operation, andtherefore only one such device will be described, like elements ofeachdevice being given like reference numerals as the description proceeds.

Support means for the various movable elements of the device 66 isfurther provided by a pair of pivot blocks 73, 75 and a centrallylocated pivot block 74 whichare each fixedly mounted on the plate 68.The pivot block 74 has an opening therein for receiving a pin 78 andpair of pneumatic cylinders 80 and 82 of the double-action type in turneach receive the pin 78 in pivotal engagement. Each of the cylinders 80and 82 are further provided with a pivotal connection to a pair of pins84 and 86 respectively which are received in the blocks 73 and 75. Thecylinder 82 is thereby pivotally attached between the blocks 74 and 73,while the cylinder 80 is independently, pivotally supported between theblocks 74 and 75.

The cylinder 82, as best shown in FIG. 2, is provided with an anglemember 88 connected to a piston rod 90 activated by fluid pressure inthe cylinder. A guide pin 92 is received in a flanged portion of thecylinder 82 for slidable movement, and

t has one end connected to the angle member 88 to thus add rigidity tothe member and prevent rotational movement thereof during operationofthe device.

Likewise, the cylinder 80 has a piston rod 94 connected to an anglemember 96 which is connected to a slidable guide pin 98, all of whichare designed to operate similar to the elements described in connectionwith the cylinder 82.

Referring now to FIGS. 3 through 5, taken in connection with FIG. 2, itwill be observed that the angle members 96 and 88 comprise a downwardlyextending tab portion terminating adjacent the face of the stack S. Thetab portion of the members 88 and 96 are each provided with a means forengaging the face surface of the stack S, in the form of strips of cardcloth 100 and 102. The card cloth elements [00 and 102 are oriented suchthat their points are directed toward the pickoff elements 62 therebyproviding pushing action to the engaged sheet when moved in thatdirection.

While the unidirectional frictional quality of the card cloth elements100 and 102 lend that material particularly useful in this application,it should herein be brought out that the ele ments S8 and 96 might alsobe provided with a plurality of sharp pins having their ends orientedtoward the pickoff member 62, or a sticky tape material, etc., each ofwhich may be desirable for a particular application.-

lt has further been found that in many applications where the specificdevice 66 is to be employed with sheets having a wide range ofthickness, the use of sharp pins which are readily interchangeable orare adjustable in length, is highly desirablc.

In addition to pivotally attaching the cylinders 80 and 82 to the blocks73 and 75 the pins 84 and 86 serve to pivotally attach a pair ofsubstantially parallel arms 104 and 106 to the separating device 66. Thearms 104 and 106 extend over the stack 5 and are independentlymovabiewith respect to the cylinders 80 and 82, and to each other.As'best shown in FIG. 3, the arm 104 is provided with an angle bracket108, having one flange provided with a pair of slotted openings throughwhich a pair of fasteners are received to adjustably attach the bracketto the arm 104. The lowermost flange of the bracket 108 has an openingprovided therein through which the threaded portion of a presser foot110 is received. A nut is disposed on either side of the lowermostflange of the bracket 103, in engagement with the threaded portion ofthe foot 110, to hold the foot lockingly engaged on, but adjustable withrespect to, the flange.

As in the case with the arm 104, the opposite arm 106 is likewiseprovided with an angle bracket 112 having a lower flange provided with apresser foot 114 which depends downwardly from the arm. Each of thepresser feet 110, 114 when so disposed for pivotal movement is effectiveto contact the face of the stack 5 and provide means for applyingpressure thereto.

in viewing the construction shown in FIGS. 3, 4 and 5 it will be notedthat a clamping means is provided in the separating device 66 in theform of a vertically disposed cylinder 116 having a portion threadedlyreceived in an opening in the mounting plate 68 and held in place by alock nut. The cylinder 116 has a piston rod 118 which serves to support,and is received through an opening in, a clamping plate 120. The plate120 is adjustable along the length of the rod 118 and is held in placeby a pair of lock nuts threadedly engaged on the piston rod. As isevident from viewing FIGS. 3 and 4, the vertical cylinder 116 isattached to the mounting plate 68 in a posi tion whereby the clampingplate 120 is disposed above the stack S with the piston rod 118 in itsretracted position, but is moved to a position clamping the stack S whenthe piston rod is in the extended position. A slotted opening 122 isprovided in the plate 120 for receiving the angle members 88 and 96 intheir retracted position, thereby allowing both clamping and sliding ofthe material to be executed at substantially the same position on theface of the stack.

A pair of adjustable stops 124 and 126 are disposed beneath thecylinders 80 and 82 respectively to retain the orientation between thefabric-engaging means connected with each cylinder, and the face of thestack S, when the stack is removed from under the separating device 66by the elevator 12.

To accomplish the aforementioned separation, the sheetseparating device66 is employed as best shown in FIGS. 3, 4 and 5. Although the devices66 as shown in these FIGS. are operative to effect separation of twosheets from the stack, to be picked off in registry by the device 62 itshould here be mentioned that by closing off the fluid power to one ofthe cylinders 80 or 82, the device is effective to separate only onesheet from the stack S. It should further be evident that a third suchcylinder and related structure might be added to the construction whichwould operate in like sequential manner to provide for separation ofthree-sheets from the stack. Also, by

providing suitable means for retaining the buckled sheet in its buckledstate, such as a movable finger element depending from above the stack(not shown) it would be only necessary to repeat operation of thecylinders or 82 to buckle a plurality ofsheets, as desired.

Referring to FIG, 2 with the elevator 12 in its upper position theseparating device 66 is supported over the stack S with the lowerextremities of the members 88 and 96, and hence the card cloth and 102,contacting the face of the stack. The cylinders 80 and 82 arepressurized on one side so that the piston rods 90 and 96 are in theirretracted positions. Each of the presser feet and 114 are in contactwith the face of the stack, one being located on either side of the lineof movement of the members 88 and 96.

As with the cylinders 80 and 82, the cylinder 116 is pressurized so thatthe piston rod 118 is in the retracted position, thus locating theclamping plate in spaced relation with the face of the stack S. Themachine is now in position to feed a pair of sheets from the face of thestack.

Referring now to FIG. 3, the opposite end ofthc cylinder 80 has beenpressurized so that the member 96 is caused to slide over the face ofthe stack. The card cloth 102 contacting the face sheet becomes engagedtherewith, and causes the sheet to move over the underlying sheetsforming a buckle between the member 96 and the presser foot 114. Withthe elements so an ranged, the member 88 now rests on the secondmostface sheet of the stack, the face sheet having easily slid from underthe card cloth 100 when moved in the direction of the engaging points ofthe card cloth. The clamping plate 120 is still maintained above thestack S, the onlycylinder actuated being that connected to the member96. 1

Referring to FIG. 4, the cylinder 32 has now been actuated such that themember 88 is moved forwardly towards the presser feet 110, 114 so that abuckle forms in the now face sheet of the stack S between the member 88and the presser feet 110, 114, directly behind the member 96. Thecylinder 116 is now actuated so that the clamping plate 120 is forceddownwardly upon the stack S to clamp the third sheet and underlyingsheets in place while the pickoffmembcr 62 is moved away from theseparating devices 66 carrying, with it the two face sheets which havebeen separated from the stack S.

Additionally, the elevator 12 may be lowered during operation of thepickoff device 62 to facilitate removal of the separated sheets from thestack, the elevator then being reciprocated to substantially its initialposition to start a new cycle. The elevator 12 when returned upwardly isgenerally positioned so that the top of the stack is alwayssubstantially at the same position relative to the device 66. The plate120 is also positioned in the device 66 such that it maintains itseffectiveness over the initial portion of elevator downward travel.

While the operation has been described with regard to one device 66, itshould be understood that each of the cylinders 82, 80 and 116 areconnected to a common source of fluid pressure such that operation ofthe devices to separate the stack is sequentially synchronized.

Although the specific circuitry involved in pressurizing the cylinders80, 82 and 116 in sequence has not been described in detail, it isconsidered that various workable arrangements employing both electricaland pneumatic components could be evolved by one skilled in the art,andtherefore, will not be herein described in detail.

The machine as herein described comprises two-separating devices 66.However, it should be evident that applications may exist where a singledevice 66 could be employed, or wherein more than two such devices wouldbe necessary to adequately separate the material.

However, it has been found that for most applications in the garmenttrade, wherein average size sheets of fabric material are fed, the twodevices 66 are sufficient to adequately control separation and movementof the material from the stack S.

Also, it might be mentioned, that having two separator devices 66 actingon the stack 5 give the redundency or failsafe condition wherein onlywhen both units incorrectly separate does a malfunction exist in thefeeding process.

Additionally, it should herein be brought out that the location of thedevices 66 at the corners of the stack has proved advantageous in thegreater number of fabric shapes involved in the garment trade. While theinvention herein described is not considered to be limited to use of theseparating devices 66 at the corners of the stacks, such arrangement hasproved advantageous in most stacks having such corners available.

- It has also been found that for very stiff materials the presserfeet'll4 and 110 may be swung back out of use whereby the bucklescreated by the members 88 and 96 become much larger,.the material beingforced against the pick up 62 rather than the presser feet. r

' The various features and advantages of the invention are thought to beclear from the foregoing description. Various other features andadvantages not specifically enumerated will undoubtedly occur to thoseversed in the art, as likewise will many variations and modifications ofthe preferred embodiment illustrated, all of which may be achievedwithout departing from the spirit and scope of the invention asdefinedby the following claims.

We claim:

1. A machine for feeding flexible sheets from a stack thereofcomprising:

pickoff means for engaging the ing the sheets therefrom;

and mechanism for separating a preselected number of sheets from thestack, said mechanism having a plurality of means disposed adjacent thestack for engaging the surface of the face sheet of the stack andmovable in a common direction;

said separating mechanism further including a pair of presserfeetdisposed one on either side of the path of travel of each of saidsurface-engaging means for applying pressure to the face of the stack ata location spaced from each of the surface-engaging'means in thedirection of movement of said surface-engaging means whereby a face ofthe stack and removbuckle is formed in each of the engaged sheetsbetween the respective engaging means and said presser feet duringmovement of the respective engaging means;

means for moving said surface-engaging means in a direction having acomponent substantially parallel to the face of the stack to slide theface sheet over the underlying sheets to separate the face sheettherefrom; other means disposed adjacent to the stack for engaging thesurface of the now face sheet in the area where the face sheet is movedoff the stack; v

means for moving said other means in a direction having a 4 componentsubstantially parallel to the face of the stack to slide the engaged'nowface sheet over its underlying sheets to cause separation of the sheettherefrom; and

means for applying a clamping pressure to the underlying sheets of thestack in the area where the now face sheet is moved from over theunderlying sheets.

2. A machine in accordance with claim 1 wherein said separatingmechanism further includes support means disposed above the stack andwherein said presser feet and said respective surface-engaging means areeach pivotally connected to said support means for independent movementtoward and away from the stack face.

3. A machine in accordance with claim 1 which comprises at least a pairof said separating mechanisms, said mechanisms being disposed atopposite sides of said pickoff means and rearwardly thereof with respectto the sheet pickoff movement ofsaid means.

4. A machine in accordance with claim 3 wherein said separatingmechanisms are located adjacent opposite corners of the stack and saidsurface-engaging means'of one separat ing mechanism is disposed formovement with a component towards each surface-engaging means of theother device in sliding an engaged sheet over the underlying'sheets.

